D defs.my
Entry 1 sense Webster, 1913

Irreversible steering gear

· Ir·re·vers·i·ble steering gear · IPA
01 A steering gear, esp. for an automobile, not affected by the road wheels, as when they strike an obstacle side ways, but easily controlled …
  1. 1.
    A steering gear, esp. for an automobile, not affected by the road wheels, as when they strike an obstacle side ways, but easily controlled by the hand wheel or steering lever.(Mach.)